The present disclosure relates generally to electrical current and magnetic field sensing devices. More particularly, the present disclosure relates to a micro-electromechanical system (MEMS)-based current and magnetic field sensor.
A current carrying conductor produces a magnetic field in the vicinity of the current carrying conductor. The magnetic field produced by the current carrying conductor can induce a force on another current carrying conductor disposed in the magnetic field produced by that current carrying conductor. As such, one approach used to sense electrical current involves the use of a sensor that measures the magnetic field induced by current flowing in a current carrying conductor. Since the generated magnetic field is proportional to the current flowing in the current carrying conductor, such a sensor can use the magnitude of the magnetic field to determine the current.
From a safety perspective, current sensors that use magnetic fields to measure electrical current are well suited for high voltage applications because they do not have to contact the high voltage circuitry. However, there are several disadvantages associated with existing current sensors that use magnetic fields to measure electrical current in high voltage applications. For example, existing current sensors tend to have a large form factor because they require a thick conductor that can withstand the varying levels of current flow that can be experienced. Additionally, the current flow induces heating, which reduces the efficiency and accuracy of the current sensors. Since existing current sensors are large and bulky, their physical and electrical operating characteristics have prevented their use in smaller scale environments.
Recently, micro-electromechanical systems have been utilized as current sensors. However, many of theses micro-electromechanical system current sensors are susceptible to environmental factors that impact their accuracy.
There accordingly remains a need in the art for a MEMS-based magnetic filed sensor capable of producing accurate readings in an environment that includes interference.